<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>

let arr = [2, 6, 18, 15, 40]
      let sum = 0
      for (let i = 0; i < arr.length; i++) {
        if (arr[i] % 3 === 0 && arr[i] % 2 === 0) {
          sum += 1
        }
      }
      document.write(`能被3整除的偶数的个数是: ${sum}`)

  </script>
</body>
</html>